DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 9-10/2008 str. 31 <-- 31 --> PDF |
N. Pernar, D. Bakšić, V. Bobić, I. Perković: STANJE TLA U MIKRODEPRESIJAMA ŠUME ŽUTICA Šumarski list br. 9–10, CXXXII (2008), 405-417 phenomena, resulting from the disturbed ecological balance, are associated with intensive commercial activities in the area during the period mentioned above. The basic hypothesis is that the ecosystem has undergone complex disturbance, which is associated with the following: oil well fluid spills in the past 40 years, hydrological changes resulting from a dense road network built to serve the needs of the oil-gas field and forest management. To a lesser extent, it is also linked with hydrological and microbiological changes associated with occasional retention of floodwater. The purpose of our research was to identify some possible causes of these occurrences from the aspect of chemical and biological soil condition. We focused on the analysis and monitoring of chemical and biological properties of the surface soil in the lowest localities (microdepressions). Phosphorus and potassium concentrations and trace elements were investigated, and so were mineral oils and total lipoidal substances, as well as microbiological activity. The research is based on twice-yearly measurements of the above parameters in 14 points in those microdepressions whose location (e.g. in relation to some possible contamination with oil well fluids), as well as the occurrence of pedunculate oak dieback has led us to conclude that they represent micro-sites most exposed to the mentioned impacts. Although the forest of Žutica is a homogeneous area in geographic and relief terms, the surface part of the soil in this forest has proved to be physiographically highly heterogeneous. With regard to oil carbohydrates, the soil is not contaminated over larger areas. Therefore, contamination as such is not considered responsible for tree dieback over larger areas. Permanent sources of pollution at the level of very weak contamination are associated with restored mud ditch, but they are probably not reflected on the wider Žutica area. Microbiological parameters indicate populations of adapted micro-organisms which ar The concentration of trace elements in the soil is within geogenic values, whereas some occasional anomalies occur in the locations which have been recovered after oil well fluid spills. K e y w o rd s : forest soil, contamination soil, forest Žutica. |